Originally Posted by
maartendc
Also, the rear wheel is a Velocity Aerohead O/C, meaning that the rim is off-center, or not symmetrical. Does that mean the spokes on one side are shorter / longer than on the other side? Does that mean I need another O/C rim if I want to reuse the spokes?
Since the rim doesn't sit centered between the hub flanges on wheels with external gears, it's very common for wheels to have different spoke lengths on DriveSide(DS) and NDS.
With an OC rim the nipple holes end up a little closer to flange center. Possibly, but not guaranteed, to allow the same length spokes to be used.
I recommend you remove one spoke from each side and measure what you got to be able to do a good prediction WRT spoke reuse.